The proposed research is designed to demonstrate the functionality, safety and effectiveness of an innovative disposable retractable trocar system intended for thoracostomy and chest tube insertion. When tension pneumothorax is suspected, the conventional clinical procedure is to perform a needle thoracostomy, in which a large needle is thrust blindly through the anterior chest to decompress the pneumothorax emergently. When pneumothoracies, hemothoracies, pleural effusions and empyemas occur, insertion of a chest tube is indicated, requiring a combination of sharp and blunt dissection to gain access to the pleural space. Our new device for chest access is similar in concept to retractable tracers used in pararascopic surgery. Preliminary testing in swine indicate chest tube thoracostomy with the retractable trocar is quicker and easier, results are more uniform, and it is thus presumably safer than techniques used currently. We propose to conduct a clinical study to evaluate device, safety, and effectiveness. This research is expected to lead to new and improved methods for emergency management of traumatic chest injury. PROPOSED COMMERCIAL APPLICATIONS: The low cost disposable thoracostomy trocar and chest tube delivery system could be used by paramedics, emergency physicians, trauma surgeons, intensivists and anesthesiologists, all of whom encounter patients with pneumothoracies and other acute pleural processes. This minimally invasive device could become the new standard of care. The next evolution will put our automatically retracting, twin-bladed incision mechanisms of laparoscopic trocars-a huge potential market.